Okla. Stat. tit. 12, § 12-2806: Attacking and supporting credibility of declarant

When a hearsay statement, or a statement defined in subparagraph

b, c, d or e of paragraph 2 of subsection B of Section 2801 of this

title, has been admitted in evidence, the credibility of the

declarant may be attacked and, if attacked, may be supported by any

evidence which would be admissible for those purposes if declarant

had testified as a witness. Evidence of a statement or conduct by

the declarant at any time, inconsistent with the declarant’s hearsay

statement, is not subject to any requirement that the declarant may

have been afforded an opportunity to deny or explain. If the party

against whom a hearsay statement has been admitted calls the

declarant as a witness, the party is entitled to examine the

declarant on the statement as if under cross-examination.